Fastener assembly

ABSTRACT

A fastener assembly includes a grommet, a dampening subassembly, and a pin. The pin is secured to the grommet and the dampening subassembly. The pin is configured to rotate between a locked position and an unlocked position with respect to the grommet. The pin secures to the grommet in the locked position, and is removable from the grommet in the unlocked position.

RELATED APPLICATIONS

This application relates to and claims priority benefits from U.S.Provisional Patent Application 60/675,795 entitled “Pin And GrommetAssembly,” filed Apr. 28, 2005, which is incorporated by referenceherein in its entirety.

FIELD OF THE INVENTION

Embodiments of the present invention generally relate to fasteners, andmore particularly, fastening systems including a pin and grommet.

BACKGROUND OF THE INVENTION

Grommet assemblies that may be used for mounting a motor to a supportsurface are known. For example, U.S. Pat. No. 4,522,378, entitled “WiperMotor Mounting Grommet” (the '378 patent) discloses a one-piece integralresilient grommet of elastomeric material. The '378 patent describes atypical grommet assembly that isolates the vibration and noise that ispropagated from a motor. The grommet disclosed in the '378 patent may beused with electric motor assemblies including fractional horsepowerengines, such as those used with rear windshield wiper systems ofcertain vehicles.

FIG. 1 illustrates an isometric exploded view of a conventional grommetassembly 10, such as shown and described in the '378 patent. Theassembly 10 includes a rivet nut 12, a metal bushing 14, a rubberdampener 16, and a metal bolt 18. A supplier receives the metal bushing14 and the dampener 16 and assembles them with respect to a motorassembly. The supplier then provides the motor assembly, including themetal bushing 14 and the dampener 16, to an original equipmentmanufacturer (OEM).

The OEM then further secures the separate rivet nut 12 and the metalbolt 18 to the metal bushing 14 and the dampener 16. In particular, therivet nut 12 is inserted and installed to sheet metal by a firstoperator at a first station. Typically, the rivet nut 12 is positionedwith respect to the sheet metal and engaged with a rivet gun to bond therivet nut 12 to the sheet metal. Then, a second operator locates themotor assembly to the sheet metal, and locates and pre-dives the metalbolt 18 at separate locations. The second operator then drives the metalbolts 18 to the specified torque rating, at which point the assemblyprocess is complete.

Typically, a supplier utilizes a certain number of components, forexample, seven components, i.e., one motor, three bushings, and 3dampeners, and three assembly operations (one for each location).Additionally, the OEM typically utilizes a certain number of components,for example, seven components, i.e., one motor, three metal nuts, andthree metal bolts) and a certain number of assembly operations, forexample, ten assembly operations. If the motor assembly is to beserviced, each metal bolt 18 is rotated numerous times until itdisengages from each corresponding rivet nut 12 in order to remove themotor assembly from the structure to which it is secured (such as apiece of sheet metal).

Overall, the process of assembling a conventional grommet assembly to amotor may be time and labor intensive. Further, the process of servicinga motor that is secured to a structure with conventional grommetassemblies is also time and labor intensive due to the fact that anoperator engages each bolt separately with a tool and rotates each boltnumerous times to remove the motor from the structure.

Thus, a need exists for an improved assembly that allows for efficientassembly. Additionally, a need exists for an assembly that allows adevice, such as a motor assembly to be quickly and easily removed from astructure to which it is secured.

SUMMARY OF THE INVENTION

Certain embodiments of the present invention provide a fastener assemblythat is configured to secure a device, such as a motor assembly, to astructure, such as a piece of sheet metal. The fastener assemblyincludes a grommet, a dampener, a bushing, and a pin, all of which mayinclude cored-out portions. The fastener assembly may be shipped to anoriginal equipment manufacturer as a single unit.

The grommet includes at least one pin retention member. The dampenerincludes a generally cylindrical main body having at least one grooveconfigured to retain a reciprocal feature of the structure. The bushingis secured within the dampener. In particular, the bushing may be moldedwith the dampener.

The pin is rotatably secured to the grommet by the pin retention membersecuring to the detent. The pin snapably secures to the bushing througha securing interface. The pin rotates between a locked position and anunlocked position with respect to the grommet. The pin secures to thegrommet in the locked position, and is removable from the grommet in theunlocked position. The securing interface between the bushing and thepin may be broken when the pin rotates relative to the bushing.

The pin retention member may include pin retention legs having endscanted toward the pin. The detent may include retention recesses. Theends may be secured within the retention recesses in the lockedposition, and rotation of the pin into the unlocked position spreads thepin retention legs open, thereby removing the ends from the retentionrecesses.

The grommet may also include flex arms configured to secure the grommetwithin a hole of the structure. The pin includes a shank having anintermediate clearance portion, which may have an hourglass shape. Theintermediate clearance portion allows the flex arms to flex toward thepin without the flex arms engaging the pin.

The pin may also include at least one pin stop block, and the grommetmay also include at least one grommet stop block. The locked or unlockedposition may be indicated when the pin stop block abuts the grommet stopblock upon rotation of the pin.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates an isometric exploded view of a conventional grommetassembly.

FIG. 2 illustrates an isometric partially-exploded view of a fastenerassembly according to an embodiment of the present invention.

FIG. 3 illustrates a motor assembly according to an embodiment of thepresent invention.

FIG. 4 illustrates an isometric view of a dampening assembly securablyretained within a mounting flange of a motor assembly according to anembodiment of the present invention.

FIG. 5 illustrates a front view of a pin according to an embodiment ofthe present invention.

FIG. 6 illustrates a side view of a pin according to an embodiment ofthe present invention.

FIG. 7 illustrates a plan view of an engagement knob of a pin accordingto an embodiment of the present invention.

FIG. 8 illustrates an isometric view of a bushing according to anembodiment of the present invention.

FIG. 9 illustrates an isometric view of a pin mating with a bushingaccording to an embodiment of the present invention.

FIG. 10 illustrates a cross-sectional view of a pin and bushing throughline 10-10 of FIG. 9.

FIG. 11 illustrates an isometric view of a dampener according to anembodiment of he present invention.

FIG. 12 illustrates a plan view of a dampener according to an embodimentof the present invention.

FIG. 13 illustrates a cross-sectional view of a dampener through line13-13 of FIG. 12.

FIG. 14 illustrates a front view of a grommet according to an embodimentof the present invention.

FIG. 15 illustrates a side view of a grommet according to an embodimentof the present invention.

FIG. 16 illustrates a top plan view of a grommet according to anembodiment of the present invention.

FIG. 17 illustrates a transverse cross-sectional view of a fastenerassembly according to an embodiment of the present invention.

FIG. 18 illustrates an axial cross-sectional view of a pin in a lockedposition with respect to a grommet according to an embodiment of thepresent invention.

FIG. 19 illustrates an axial cross-sectional view a pin in an unlockedposition with respect to a grommet according to an embodiment of thepresent invention.

Before the embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of the components setforth in the following description or illustrated in the drawings. Theinvention is capable of other embodiments and of being practiced orbeing carried out in various ways. Also, it is to be understood that thephraseology and terminology used herein are for the purpose ofdescription and should not be regarded as limiting. The use of“including” and “comprising” and variations thereof is meant toencompass the items listed thereafter and equivalents thereof as well asadditional items and equivalents thereof.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 2 illustrates an isometric partially-exploded view of a fastenerassembly 20 according to an embodiment of the present invention. Theassembly 20 includes a grommet 22, and a pin 24 secured within adampening assembly 26. The pin 24 is configured to be removably androtatably secured, such as by snap engagement, to the grommet 22. Aparts manufacturer provides the fastener assembly 20 as shown in FIG. 1to a supplier or distributor. The pin 24 may be assembled to thedampening assembly 26 prior to the pin 24 being secured to the grommet22. Optionally, the fastener assembly 20 may be shipped with the grommet22 attached to the pin 24, which is in turn secured to the dampeningassembly 26. Alternatively, the fastener assembly 20 may be shipped suchthat the grommet 22 is not attached to the pin 24.

FIG. 3 illustrates a motor assembly 28 according to an embodiment of thepresent invention. The motor assembly 28 includes a motor 30 mounted toa rigid plastic mounting bracket 32 by metal bolts 34. For example, themotor 30 may be secured to the plastic mounting bracket 32 by any numberof bolts 34, such as five or six. The mounting bracket 32 includesc-shaped mounting flanges 36 configured to receive and retain thefastener assembly 20. The dampening assembly 26 of the fastener assembly20 may collapse as it is inserted through the open end of the rigidmounting flange 36. The dampening assembly 26 is securably retainedwithin the mounting flange by compression and friction between thedampening assembly 26 and the mounting flange 36.

FIG. 4 illustrates an isometric view of the dampening assembly 26securably retained within the mounting flange 36 of the motor assembly28. The supplier assembles the dampening assembly 26, which securablyretains the pin 24. The supplier then mounts the assembled fastenerassembly 20 into the mounting flange 36. The grommets 22 may or may notbe secured to the pins 24 at this stage. The supplier then provides themotor assembly 28, including the fastening assemblies 20, to the OEMassembly plant. As such, the OEM assembly plant receives a single motorassembly 28 having a plurality of fastening assemblies 20 alreadyinstalled. An operator at the OEM assembly plant may then install themotor assembly 28 to sheet metal, or another such structure, by engagingthe pins 24 of each fastener assembly 20 at each fastener location.

Thus, embodiments of the present invention provide an assembly processthat may include seven components, i.e., one motor assembly 28, threepin 24 and dampener assemblies 26, and three grommets 22. The pins 24may be secured to the grommets 22, and the resulting fasteningassemblies 20 are then installed at corresponding portions, i.e.,mounting flanges 36, of the motor assembly 28. The OEM assembly plantthen receives the completed motor assembly 28 and an operator performssimple assembly operations, such as engaging each pin 24 to secure themto appropriate fastening locations, to secure the motor assembly 28 to asuitable material, such as sheet metal.

FIG. 5 illustrates a front view of the pin 24. The pin 24 includes ashank 38 integrally formed with a engagement knob 40 at an upper end,and a mating tip or nose 42 at a lower end. A retainer recess 41 isformed between the engagement knob 40 and the shank 38. The engagementknob 40 is configured to be manipulated by an operator to secure andremove the fastener assembly 20 (shown in FIGS. 2-4) from a reciprocalstructure, such as a hole in sheet metal. The shank 38 is generally alongitudinal body having a reduced, hour-glass intermediate clearanceportion 44 integrally formed with an elliptical camming portion 46. Theintermediate clearance portion 44 allows clearance behind panelretention legs, as discussed below. As shown in FIG. 5, the frontprofile of the elliptical camming portion 46 is relatively straight.That is, there are no notches formed between the mating tip 42 and thecamming portion 46.

The axial cross-section of the shank 38 of the pin 24 may be triangular,rectangular, pentagonal, hexagonal, or the like, so that the shank 38does not inadvertently rotate while secured to the grommet 22, asdiscussed below. Alternatively, the shank 38 may be a smooth cylinder.

FIG. 6 illustrates a side view of the pin 24. As shown in FIG. 6, theside profile of the camming portion 46 includes retaining recesses,divots, catches, or other such detents 47 configured to snapably retainreciprocal structures on the grommet 22 (shown, for example, in FIG. 2).Thus, in one position (as shown in FIG. 5), the camming portion 46 doesnot have any features to engage or retain reciprocal structures on thegrommet 22. However, when the pin 24 is rotated, the retaining recesses47 of the camming portion 46 come into contact with reciprocalstructures on the grommet 22, as discussed below, thereby securing thepin 24 to the grommet 22.

While the pin 24 is described as having a shank 38, and particularly acamming portion 46, having an elliptical axial cross-section (that is,having first axis having a first length, and a second axis having asecond length, which is different from the first length), the shank 38and camming portion 46 may be of various shapes having variable radii.For example, the camming portion 46 may be triangular. The shape of thecamming portion 46 is such that it provides a cam action when rotated,thereby spreading reciprocal structures on the grommet 22 in order toallow the pin 24 to be removed from a reciprocal structure, such as ahole formed in sheet metal.

As shown in FIG. 5 and 6, a series of stop blocks 45 may extendoutwardly from the shank 38. The stop blocks 45 are configured to engagecorresponding structures within the grommet 22 (shown, for example, inFIG. 2) to notify an operator when the pin 24 is in an unlocked positionand/or locked position with respect to the grommet 22, as discussedbelow with respect to FIGS. 18 and 19.

FIG. 7 illustrates a plan view of the engagement knob 40 of the pin 24.The engagement knob 40 is ergonomically designed to allow for easymanipulation by an operator. That is, the engagement knob 40 is largeenough to be grasped between a thumb and an index finger, and configuredto be easily rotated by a force exerted by the thumb and index finger.The engagement knob 40 may include a lock arrow 48 and an unlock arrow49 in order to instruct an operator how to lock and unlock the fastenerassembly 20 (shown in FIG. 2-4). While the lock arrow 48 and the unlockarrow 49 are shown in particular directions, the pin 24 may beconfigured so that the directions are reversed.

FIG. 8 illustrates an isometric view of a bushing 50 according to anembodiment of the present invention. The bushing 50 includes a planarsurface, such as a ledge 52, integrally formed with a cylindricalhousing 54. A pin passage 56 is formed through the ledge 52 and thecylindrical housing 54. A series of notches 58 are formed between blocks60 extending underneath the ledge 52. The pin passage 56 includes aplurality of inwardly extending tabs 62 separated by notches 64.

FIG. 9 illustrates an isometric view of the pin 24 mating with thebushing 50. The pin 24 is urged into the bushing 50 in the direction ofarrow A. As the pin 24 is slid into the pin passage 56, outwardlyextending ribs 66 formed on the shank 38 are mated into the notches 64formed in the pin passage 56. At the same time, the tabs 62 mate withchannels 68 formed between the ribs 66 of the shank 38. The matingbetween the ribs 66 and the notches 64, and the tabs 62 and channels 68interlocks the pin 24 to the bushing 50.

FIG. 10 illustrates a cross-sectional view of the pin 24 and the bushing50 through line 10-10 of FIG. 9. The pin 24 is urged into the bushing 50until the engagement knob 40 abuts the ledge 52. The bushing 50 alsoincludes a retainer ring 70 formed around the pin passage 56 proximatethe ledge 52. The retainer ring 70 snapably engages the retainer recess41 of the pin 24, thereby snapably securing the bushing 50 to the pin24. However, the interface between the retainer ring 70 and the retainerrecess 41 may be configured to break when the pin 24 is rotated relativeto the bushing 50. That is, when the pin 24 is rotatably secured to thegrommet 22 (shown, for example, in FIG. 2), and the bushing 50 issecured within the dampening assembly 26, which is in turn secured tothe motor assembly 28 (shown, for example, in FIG. 2), a rotation of thepin 24 with respect to the grommet 22 may break the securing interfacebetween the bushing 50, which may be fixed in position, and the pin 24.Thus, the securing interface between the bushing 50 and the pin 24 actsas a tether to secure the pin 24 to the bushing 50 during shipping, butnot necessarily when the fastener assembly 20 (shown, for example, inFIG. 2) securely connects the motor assembly 28 to a piece of sheetmetal. While the pin 24 and the bushing 50 are shown as two separatepieces, the pin 24 may alternatively be integrally formed with thebushing 50 as a single molded unit.

FIG. 11 illustrates an isometric view of a dampener 72 according to anembodiment of he present invention. The dampener 72 may be molded aroundthe bushing 50 (shown, for example, in FIG. 8). Molding the dampener 72in this fashion saves manufacturing cost and time. Alternatively, thedampener 72 and the bushing 50 may be individual components assembledtogether.

The dampener 72 includes a main body 74 that may be formed of anresilient material, such as plastic or rubber, that is capable ofabsorbing vibrations, such as those caused by resonance within a motor.The main body 74 is generally cylindrical in nature and includes abushing cavity 76 formed therethrough. A groove 78 is formed through andaround a mid-section of the dampener 72. The groove 78 is configured tobe received and retained by a reciprocal structure, such as a ridge,formed within the mounting flange 36 (shown, for example, in FIGS. 3 and4) of the motor assembly 28 (shown, for example, in FIGS. 3 and 4).

FIG. 12 illustrates a plan view of the dampener 72. A circumferentialbushing ledge 80 is formed within the bushing cavity 76 and includes aplurality of inwardly-extending blocks 82 separated by spaces 84.Optionally, the blocks 82 may be spaces that are separated byelastomeric walls, which may take the place of spaces 84. The blocks 82and spaces 84 are configured to cooperate with the notches 58 (shown,for example, in FIG. 8) and blocks 60 (shown, for example, in FIG. 8),respectively, of the bushing 50 (shown, for example, in FIG. 8) in orderto retain the bushing 50 within the dampener 72.

FIG. 13 illustrates a cross-sectional view of the dampener 72 throughline 13-13 of FIG. 12. As noted above, the bushing 50 shown in FIG. 8 isconfigured to be retained within the bushing cavity 76. A resilientridge 88 overhanging portions of the blocks 82 and spaces 84 isconfigured to snap over the ledge 52 (shown in FIG. 8) of the bushing 50in order to snapably secure the bushing 50 within the dampener 72 (asshown, for example, in FIG. 17) so that the bushing 50 does not rotaterelative to the dampener 72. The dampener 72 mates with the bushing 50to form the dampening assembly 26 (shown in FIG. 2). While the bushing50 and the dampener 72 are shown as separate and distinct components,the dampening assembly 26 may be molded as a single piece in which thebushing 50 is integrally formed with the dampener 72.

FIGS. 14, 15, and 16 illustrate front, side, and top plan views,respectively, of the grommet 22. Referring to FIG. 14-16, the grommet 22includes a main body 90 including a top planar head 92 integrally formedwith opposed pin retention legs 94. A pin passage 96 is formed throughthe head 92 and between the pin retention legs 94. The pin 24 (shown,for example, in FIGS. 5 and 6) is configured to be retained within thepin passage 96 by the pin retention legs 94. The grommet 22 alsoincludes flexible ramped members 98, which are integrally connected tothe pin retention legs 94 and/or the main body 90, configured tosnapably secure the grommet 22 to a piece of sheet metal with respect toa hole within the sheet metal. As such, the planar piece of sheet metalis secured between upper edges 100 of the ramped members 98 and a lowersurface 102 of the head 92.

As shown in FIG. 16, in particular, top surfaces 99 of the rampedmembers 98 comprise recessed areas 101 configured to receive a distalend of a tool, such as a screwdriver, needle-nose pliers, or the like.The distal end of the tool may be positioned within the recessed areas101 to manipulate the ramped members 98 in order to pivot them inwardly.As the ramped members 98 are inwardly pivoted, the upper edges 100 loseengagement with an underside of the planer sheet metal. The grommet 22may then be removed from the sheet metal hole.

FIG. 17 illustrates a transverse cross-sectional view of the fastenerassembly 20. As the mating tip 42 of the pin 24 is urged into the pinpassage 96, the camming portion 46 contacts the pin retention legs 94.With continued urging in the direction of arrow A, the pin 24 rotateswith respect to the grommet 22 until inwardly-canted ends 110 of the pinretention legs 94 encounter the retaining recesses 47 of the pin 24. Atthis point, the canted ends 110 snap into the retaining recesses 47. Assuch, the pin retention legs 94 of the grommet snapably retain the pin24 by snapably mating into the retaining recesses 47. Thus, a fullyassembled fastener assembly 20 may be manufactured. The fully-assembledfastener assembly 20 may then be secured within mounting flanges 36(shown, for example, in FIG. 2) of the motor assembly 28 (shown, forexample, in FIG. 2). An operator may then push the fastening assemblies20 into reciprocal holes in sheet metal to secure the motor assemblythereto.

Optionally, the grommets 22 may be separately provided to an operatorwho may first position the grommets 22 in reciprocal holes of astructure, such as a planer piece of sheet metal. The pins 24, which aresecured to the dampening assemblies 26, which are in turn secured to themotor assembly 28, may then be mated into the grommets 22. That is, thefastener assembly 20 may be provided to an OEM fully assembled with thegrommet 22, or the grommet 22 may be separately provided to theoperator.

As the fastener assembly 20 is urged into a hole, the ramped members 98of the grommet 22 are forced inward in the direction of arcs D as theypass through the hole. However, the intermediate clearance portion 44 ofthe shank 38 ensures that the pin 24 does not interfere with, engage,abut, or snag the ramped members 98. That is, the intermediate clearanceportion 44 allows clearance behind the ramped members 98 and the pinretention legs 94, thereby allowing those components to move toward theshank 38 without snagging, abutting, or otherwise engaging the shank 38.Thus, when the grommet 22 is installed into a metal sheet hole, theramped members 98 are able to move inwardly, or flex, without hitting orcrashing into the pin 24, thereby ensuring that the grommet 22 isproperly secured within the sheet metal hole.

In order to remove the pin 24 from the grommet 22, a user manipulatesthe engagement knob 40 to rotate the pin 24 in the direction of arc B.As the pin 24 is rotated, the retaining recesses 47 are rotated out ofengagement with the canted ends 110, and the increasing radius of thecamming portion 46 of the pin 24 spreads the pin retention legs 94 openin the direction of arrow C. Once the canted ends 110 are fully removedfrom the retaining recesses 47, the pin 24 may be removed from thegrommet 22 in the direction of arrow A′.

FIG. 18 illustrates an axial cross-sectional view of the pin 24 in alocked position with respect to the grommet 22. As shown in FIG. 18, theaxial profiles of the pin 24 and the grommet 22 indicate that the pin 24includes two outwardly-extending stop blocks 120 and 121 (which may bestop blocks 45 and 46 discussed above), while the grommet 22 includestwo sets of inwardly-extending stop blocks 122 and 123. Optionally, thepin 24 may include sets of stop blocks, and/or the grommet 22 mayinclude single stop blocks.

Referring to FIGS. 17 and 18, in the locked position, in which theretaining recesses 47 snapably retain the inwardly-canted ends 110 ofthe pin retention legs 94, the stop block 120 abuts against stop blockset 122 while the stop block 121 abuts against the stop block set 123.As such, the pin 24 cannot be rotated any more in the direction of arcB′, thereby indicating that the pin 24 is in a locked position.

When the pin 24 is rotated to spread the pin retention legs 94, energyis stored within the pin retention legs 94 in the form of a springforce. The pin retention legs 94 flex back to their original orientationto relieve the spring force. Thus, the pin 24 will automatically rotateback to a locked position. Therefore, the fastener assembly 20 includesa built-in return spring that ensures that the pin 24 is in the lockedposition unless there is an outside rotational force exerted on the pin,such as by an operator rotating the pin 24.

As mentioned above, the axial cross-section of the shank 38 of the pin24 may be triangular, rectangular, pentagonal, hexagonal, or the like,so that the shank 38 does not inadvertently rotate while secured to thegrommet 22, as discussed below. That is, the shank 38 may includedistinct edges. A certain amount of force is used to rotate the pin 24within the grommet 22 past these edges, thereby ensuring that the pin 24does not inadvertently rotate with respect to the grommet 22.

FIG. 19 illustrates an axial cross-sectional view the pin 24 in anunlocked position with respect to the grommet 22. Referring to FIGS. 17and 19, in order to unlock the pin 24 from the grommet 22 such that theinwardly-canted ends 110 are removed from the retaining recesses 47, thepin 24 is rotated in the direction of arc B. Once rotation of the pin 24is stopped by the stop block 120 abutting against the stop block set 123and the stop block 121 abutting against the stop block set 122, the pin24 is in an unlocked position in which the inwardly-canted ends 110 ofthe grommet 22 are fully removed from the retaining recesses 47 of thepin 24. Thus, when the pin 24 can no longer be rotated in the directionof arrow B, the pin 24 is in an unlocked position with respect to thegrommet 22.

While FIGS. 18 and 19 show locking and unlocking positions in specificdirections, the fastener assembly 20 may be configured to lock andunlock in different directions. For example, the fastener assembly 20may be configured such that the locking direction is denoted by arc B,while the unlocking direction is denoted by arc B′.

Additionally, while FIGS. 18 and 19 show that rotation from an unlockedposition to a locked position is approximately 90°, the fastenerassembly 20 may be configured otherwise. For example, the fastenerassembly 20 may be configured to allow for an unlocking rotation of 30°,45°, or various other radial distances.

Also, more or less stop blocks may be used with respect to the pin 24and the grommet 22. For example, the pin 24 may include one stop block,while the grommet 22 includes one stop block.

Referring to FIG. 2-19, components of the fastener assembly 20 mayinclude cored-out regions. For example, the pin 24, the bushing 50, andthe dampener 72 may include cored-out regions, as shown. The cores areprovided for manufacturing reasons in order to control the amount ofaxial shrink of the components. In short, all plastic parts shrink asmall amount when they are removed from a mold. The amount of shrinkagedepends on the geometry (length and thickness) of the component. Pins,or any long cylinder, are susceptible to such shrinking. Thus, thecored-out regions assist in controlling the amount of shrinkage.

Thus, embodiments of the present invention provide an improved assemblythat allows for efficient assembly. The embodiments of the presentinvention offer a reduced manufacturing cost when compared withconventional grommet assemblies due to less material handling and areduced time of assembly. Additionally, embodiments of the presentinvention provide an assembly that allows for quick and easy removal ofthe device, such as a motor assembly, from another structure, such as aplanar piece of about metal, in order to service or replace the device.

Additionally, while embodiments of the present invention are discussedwith respect to motor assemblies, the fastening assemblies may be usedwith various other systems in order to fasten one structure to another.For example, the fastening assemblies may be used to securely connectcomponents of furniture, signs, light fixtures, audio-visual equipment,and various other such objects and devices.

Variations and modifications of the foregoing are within the scope ofthe present invention. It is understood that the invention disclosed anddefined herein extends to all alternative combinations of two or more ofthe individual features mentioned or evident from the text and/ordrawings. All of these different combinations constitute variousalternative aspects of the present invention. The embodiments describedherein explain the best modes known for practicing the invention andwill enable others skilled in the art to utilize the invention. Theclaims are to be construed to include alternative embodiments to theextent permitted by the prior art.

Various features of the invention are set forth in the following claims.

1-22. (canceled)
 23. A motor assembly configured to be fastened to apiece of sheet metal, the motor assembly comprising: a motor, a mountingbracket having a plurality of mounting flanges, said motor being securedto said mounting bracket, each of said mounting flanges comprising afastener assembly secured therein, said fastener assembly comprising: agrommet comprising at least one pin retention member and flex arms, saidgrommet configured to be secured within a hole formed in the piece ofsheet metal through said flex arms; a dampener comprising a generallycylindrical main body having at least one groove configured to retain areciprocal structure of the motor assembly; a bushing secured withinsaid dampener; and a pin comprising a detent and a shank having anintermediate clearance portion, said intermediate clearance portionallowing said flex arms to flex toward said pin without said flex armsengaging said pin, said pin being rotatably secured to said grommet bysaid at least one pin retention member securing to said detent, said pinsnapably securing to said brushing through a securing interface, saidpin rotating between a locked position and an unlocked position withrespect to said grommet, said pin securing to said grommet in saidlocked position, and said pin being removable from said grommet in saidunlocked position.
 24. The motor assembly of claim 23, wherein said atleast one pin retention member comprises pin retention legs having endscanted toward said pin, and said detent comprising retention recesses,said ends being secured within said retention recesses in said lockedposition, and wherein rotation of said pin into said unlocked positionspreads said pin retention legs open thereby removing said ends fromsaid retention recesses.
 25. The motor assembly of claim 23, whereinsaid securing interfice between said bushing and said pin is broken whensaid pin rotates relative to said bushing.
 26. The motor assembly ofclaim 23, wherein at least one of said grommet, said dampener, saidbushing, and said pin comprise cored-out portions.
 27. The motorassembly of claim 23, wherein said pin comprises at least one pin stopblock, and said grommet comprises at least one grommet stop block,wherein said at least one pin stop block abuts said at least one grommetstop block upon rotation of said pin to indicate at least one of saidlocked and unlocked positions.